Device for developing an electrostatic latent image, and process cartridge and image forming apparatus including the same

Abstract

A developing device develops an electrostatic latent image formed on an image carrier with toner. The developing device includes a developer carrier, a developer supplying unit that supplies a developer on the developer carrier, a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer, and an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member.

1. A developing device that develops an electrostatic latent image formed on an image carrier with toner, the developing device comprising:
 a developer carrier; 
 a developer supplying unit that supplies a developer on the developer carrier; 
 a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer; 
 an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member; and 
 an electric-potential setting unit that sets an electric potential of the layer shaping member and an electric potential of the electric-field control member. 
 
     
     
       2. The developing device according to  claim 1 , wherein an electric potential difference between the developer on the developer carrier and the layer shaping member is larger than an electric potential difference between the developer on the developer carrier and the electric-field control member. 
     
     
       3. The developing device according to  claim 2 , wherein the electric potential of the layer shaping member and the electric potential of the electric-field control member have the same polarity. 
     
     
       4. The developing device according to  claim 2 , wherein the electric potential of the layer shaping member and the electric potential of the electric-field control member have opposite polarity. 
     
     
       5. The developing device according to  claim 1 , wherein the electric-field control member is arranged within 5 millimeters from a downstream end of the shaping nip. 
     
     
       6. The developing device according to  claim 1 , wherein the layer shaping member and the electric-field control member are integrally formed via an insulating layer. 
     
     
       7. The developing device according to  claim 1 , wherein a voltage applied to the electric-field control member is variable. 
     
     
       8. The developing device according to  claim 1 , further comprising a second electric-field control member arranged upstream of the shaping nip. 
     
     
       9. The developing device according to  claim 8 , wherein the electric-field control member and the second electric-field control member are formed by forming layers of the insulating layer and the electric-field control member on a surface of the layer shaping member in order, and removing a portion of the layers of the insulating layer and the electric-field control member corresponding to the shaping nip from the surface of the layer shaping member. 
     
     
       10. A process cartridge comprising:
 an image carrier on which an electrostatic latent image is formed; and 
 a developing device that develops the electrostatic latent image formed on the image carrier with toner, the developing device including:
 a developer carrier, 
 a developer supplying unit that supplies a developer on the developer carrier, 
 a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer, 
 an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member; and 
 an electric-potential setting unit that sets an electric potential of the layer shaping member and an electric potential of the electric-field control member, wherein at least the image carrier and the developing device are provided in an integral manner. 
 
 
     
     
       11. An image forming apparatus comprising:
 a developing device that develops an electrostatic latent image formed on an image carrier with toner, 
 wherein the developing device includes:
 a developer carrier, 
 a developer supplying unit that supplies a developer on the developer carrier, 
 a layer shaping member that shapes the developer supplied on the developer carrier into a thin layer, 
 an electric-field control member that is arranged downstream of a shaping nip formed between the developer carrier and the layer shaping member and that controls an intensity of an electric field generated between the developer carrier and the layer shaping member, and 
 an electric-potential setting unit that sets an electric potential of the layer shaping member and an electric potential of the electric-field control member.